System of electric-motor control.



No. 892,419. PATENTED-VJULY 7, 190.8."

Y P. HALLOOK SYSTEM OF ELECTRIC MOTOR'GONTROL.

APPLICATION FILED DEG. 3. I905.

z sums-$133211.

WITNESSES: INVENTOR I ATTaRNE Y PATENTED JULY 7, 1908.

F. D. HAIiLOOK. SESTEM GE ELEGTRIG' MOTOR CONTROL.

APPLICATION FILED DEO.3,1906.

2 SHEETS PATENT oFFIoE."1;.,

' FIJn'roH R D.HALLQGK,'QFWVILRiNEBURG, PEN sy vANi-A ASSIGN'OR o Wh'sTINQHQUSE.

ELECTRIC & MANUFACTURING COMPANY, 'A 'conrom'rron or PENNSYLVANIA.

HS'YS'TLEM-OF eliminate-Moron coN'moL,

2,419.; Specification 0:

'Applicetion filed -Dec emherfi, 1906. Serial No. 346,078

- all whom it may concern':

:Bejit known, -tl1etj.I," F ETonEe DQ-HALg riLOCK, ajcitizen of the United 'States, anda resident of Wilkins'b-urg,=--in.= the county of Allegheny and State of Penn s'ylvania',s have invented anewand useful Improvementin Systems of, Electtic-Motor Control," of whichthe tolldwingis as 'ecificetion. f

v M invention re ates'to "ontrolling means 7 are ectrio motor's and has special-reference 'to" systems or devices which arejaclapted for starting relativelylarge motors.

The 0 ject'oit'iny invention is to proivid'e meansrthat shall be sim'plefencl durable in constructionand eflective v in operation for starting relativelv large electric motors andat. the same time 'elinnnatingJthe possibility of injuring their windin" s byincreasing'the Y Yap li'ed voltage'too rapi 1y, or starting-relatively lar e electric 'mOE tors a plurality of indepen entlywperated switches -anda "-,coo erating i resistance are sometime utilized in lieu of theordinaryforms of 'starting-rheo'stats usually employed withmotors ofthe snhaller sizeszf The severalsWi-tphes comprised in asta'rter of the aforesaid-class have sometimes-been mechanically, or electrically interlocked! in order to rev'ent the closurelof the switches in other hana predeterlnined o'rder or to' auto; "matically interruptthe niotorcir'cuit in case. the switcheswere-s'p elo'sedl g- These devices have usually been complicated-and expensive,,si1'1ce theyhave been eppliedto each switch ofthe series, and many instances the lnotor-circuit might be'unneces'sa-ril i n- .t'e'rrupted'. ,Forexainple, on switch 0 "the series-might rer'nain open, iftielload von the niot'or during .the 1 period, of startin were "light without severely; overloading t 'eylinei or injuring the motor. v According to m" 3 present"invention, by a relatively sirnple modification of the auto matic' circuit-breaker which is'ordina'ril located in the motor circuit, irrespective o the foimjof starting device, I-prevent the com-. pletion ofthe motor circuit unless and until all the switches of 'the series oomprisedinthe .motor starter areopen.

A fu'rth r advantage of niy.i'rnp1'oved;system lies iinthefact that it-may 'be afprilied equally well to any-Well known-form'o 1 e0; static controlle1' If the switches are closed I spring 32 a," latch '33 for: holdingtheiinter wees-m et. v {rewritesuly "7, mos,

' accelerating process must be re -ooin-i menced as 'above indicated.

' y mventionis illustrated inthe-jaccomf,

panyingvdrawings, in which. I Figures '1 and 2 are diagramrn'aticviews of 60" motor startin devicesarranged in accordance therewith." igs.-3and tare, respectively,

a side'- el'e'vation-anda l'an .vi-ew of a; main apircuit interrupter of we known typeqwhich f ssuitably modified for use i in connection 55 vwith the systems illustrated infFigs. land-'2;

- 'andFig-J-5 is a-frontielevation ofthe retainm me, .v

Referringto Figs. 1,3, 4; andj5 of the drawg6; ings,'elect1'ic. en'erg'y' i"s .;supplied-.from:;any cohvenientlsouree, such as generator :1, to an: electric .mot0r2 through main liri 0nduc-;

tors 3 .and, 4 and a'main circuit interrupter 15;. r The motor 2 com prises" an; armature 6, 9. se 175 ,ries; field-ma et Winding 7, and a shunt field inagnetfwin inggS, and may be. accelerated in a well known mannethyintroducing a.- starting' resistance 9into".the-motorcircuit I and gradually! diminishingthe active ,amount'iso .of this' resistanceL.7. The amount of current traversing the shunt field magnet '.vl7indin 1gh$ ing latch-and .difierentialcoils of the circuit may 'be' varied.'by-.a field rheostat 10,,

accelerating resistance: of the .motoiifis- 06111; trolled by a. series of similar me us-11y oper- 435' ated switches, =1 1, 12-, 13, "-14,, 1 5, 1'6"'a;n' i' '17, I .whiehare} connected to] the, ends :and to af I plurality of intermediate. oints in' the re-' 'sistaincej" 9'; each] oft 'esef -switches is losed, {contact I is made from thefp'oint-"of' 9 0 connection withthe resistance toone ofa so ries offcooperatifig ,contact. memhers-1'8,- all of which "are connected tea-terminal 19 of the mainf circuit interru'pter5... The min t circuit interrupter comprlse's' stationary e0I-l-- 95. vtacttermina1s19 'and2fiya'inoveble brid ing :contact member 27', a plivota'lly inqunteglever 28, an operating andle 29;. a'releese magnet 30' having .awinding's31, {an opening 100 .rupter'in its'closed position, and elpivptally mountedtri ping armatureBArl e-lever 28 is provided with lateral ro'eotionsj35 which'mey en a'ge' a'two-part ate 365'11i1d'er Predeterr'nine' conditions hereinafter; ex: 's lained. The twoert letch 36 i'sfli'n'the' orl'n of a bell-cran leverand is1; ivota.1ly mounted upona-shaft 37.]; A-spring'38 nbrihally holds the'latch 36 in'sueh aiposition so that the resistance lSlI'QdllCdtOO. ragidly the maincircuitbreakerwfl be opene and that it doesnot interfere thefreeactionl 119-- of the interrupter, but a magnetizable core 39 is adapted to oppose the spring 38 when energized by either one of a pair of diileren tial coils 40 and 41 and thereby prevent the closure of the breaker. The differential coils 40 and 41 are so connected as to neutralize each other when the switches '11, 12, 13, 14,

' or in such an irregular order as to trip the- 4 the ductor 4.

main line circuit interrupter 5, this interrupter will'be forced to its open position by the s ring 32 and will, be held in such position y the latch 36 until all of the accelerating switches are again open.

Referring particularly to Fig. 1, the circuit connections for the system may be traced as follows :Assuming that main circuit interrupter 5 and line switch 42 are closed, elec trical energy 13 supplied from the generator -1 through'line conductor 3, conductor 43, sta-.

tionary contact members 26 and 19, movable contact member. 27, overload release coil 31, and a conductor 44 to the stationary contact members 18. When the circuit--breaker 5 and the main line switch 42 are both open, energy is supplied from-line conductor 3, through conductor 46, differential coils 40 and 41,'in opposite directions, and auxiliary conductor 45110 the oppositeline conductor 4. The resultant magnetic cife ct of the coils 40 and 41 will be zero and the circuit-breaker may therefore be closed. The differential coil 40, however, is 'short-circuited as soon as the circuit-breaker 5 is closed and a circuit is com leted fromthe conductor 44' through differential coil 41 and the auxiliary conductor 45 which is connected to the line con- The energizing of the coil 41 has no eflect upon the circuit-breaker, under the conditions'just stated, because thebreaker is closed. The motor 6 may now be included in the circuit in serieswith theresista-nce 9 by closing the switch 11, whereupon circuit .will be continued from the stationary contact members 18, through switch 11, resistance 9, conductor 46, armature 6, series field magnet winding 7, and the switch 42 to the line conductor 4.- Theresistancc 9 may be gradually short-circuited to accelerate the motor by successively closing the switches 12,13, 14, .15, 16 and'17. 4 I In casean inexperienced attendant should attempt to accelerate the motor by closing the switches in other than the order indi cated above, a large momentary increase in sufficiently energize the coil 31 totrip the circuit-breaker 5. In this event,. one or more of the accelerating switches being closed and the circuit interru ter 5 being opened, circuit would be establis led from line conductor 3 through differential coil 40 and conductor 47 to the stationary contact members 18 and, from this pint, through the closed accelerating swi'tc-i, a corresponding switch 42 to the opposite line conductor 4.

41 would be thus. short-circuited and. the coil 40' would serve to 'hold the circuitbreaker 5' in its 0 en position untilall the accelerating switc ies were opened. The tripping coil 31 may also be energized of the acce crating switches are closed in the proper order but in too rapid succession.

Referring now to Fig. 2, in which. a 1nodified motor-starting arrangement is illustrated, a single knife blade switch 20, which is a d apt ed to successively engage a plurality of cooperatingst-ationary contact members 21, 22, 23, ,24 and 25 as it is closed, corresponds to the accelerating switches 11, 12, 13, 14, 15, 16 and 17 of Fig. 1, the stationary contact terminals being connected to corresponding pointsin the resistance 9. i A pair of auxiliary contact members 48 and 49 are soarranged as to be bridged by a movable contact member 50 before the switch blade makes contact with any of the main stationary contact members, so that the switch must be opened-wide, as hereinafter explained, before it is ossible to reclose the' circuit-br ealrer after it has been tripped for any reason. The interrupted auxiliary circuit 47 is connected to contacts 48 and 49 and the auxiliary circuit 46 is also capable of being interrupted, a bridging contact member 54 which engages stationary contact members 55 and 56, being so arranged as to interrupt the circuit when the circuit-breaker 5 occupies its extreme open position. The advantage of the arrangement illustrated in Fig. 2 lies in the fact that differential coils 40 and 41, as well as all of the other parts of the motor-control system, are disconnected from the supply circuit are own. The accelreation of the motor may e effected as follows-:The switch 42 and the circuit-breaker 5 may be closed in any order, provided the accelerating switch 20 is open so that-the auxiliary circuit 47 is interrupted by the stationary contact mem bers 48 and 49, since'either or both of the diiferential'coils 40 and 41 are energized. After the circuit-breaker and switch. are closed, the motor may be accelerated by slowly-closing the switch 20 which completes "a main circuit from line conductor 3, through conductor 43,circuit-breaker '5, release coil 31 conductor 44, switch blade 20, stationary the line current would result which would contact member 21, resistance. 9, armature 6,

portion of the resistance 9, motor 2, and

It will be observed that the differential co'il when the circuitbreaker and the switch 42 series field magnet winding 11 of the motor and switch 42 to: the opposite line conductor 4. IWhenthe switch is fully closed the resistance 9 is short-c'ircuit'ed andjthecirc'uit auxiliary. circuit 47.; The action of-thedifl ferential coils 40 an'd' 4'1 is substantially the same in the systems illustrated in bo th 'diagrains. The contact nie'mbers 55' and 56 are 'br id ed by'the contact member "54 when the vbrea er- 5 is rst moved awayt from its'fu'll 2o open'position so that if'either ofithe-tl'itierem tial coils becomes energized, the catch will be interposed and ill. prevent"the' complete clo sure of the motor circuit. .A' second'r elease coil 57 is shown ,in Fig.' 2 whichis dependent 25 fo'r'its operation 'upon an-abnorinal rise'inthe Voltage of the circuit 3-4, and it will be read- 4 ily understood that the opening of the circuit may be cfiected under other conditions, ac.-'

cording. to well known circuit-breaker practice. For example, such an 1nterruption may be made to depend upon a temporary decrease in voltage. I I

I desire that' variations which do not dcpart from the spirit of 1'ny;invention shall be -35. included withihits scope, and .that'only such limitation sfbeimposed as are indicated in the.

appended claims. v y g claim as-my 1nve n11 ;1\on;+. D 1-. "The combination with an electr c cl'rtending.- to open when closed, of ineans for holding the interrupter closed, and other and an automatic interrupter in the motor clrcu-it tending to open when closed, of means independent of the short -circuiting switches x for prevent-ing'theclosure of theinterrupter whenany portion of the resistance is short circuited' 'is completedfthrou'ghthe stationary contact er 5 to open and it will uit, a resistance and-amircuit interrupter.

3. 'The combination with an electric supply I circuit, amotor and a starting resistance ,"fand a plurality-of shcrt ci'r'cuiting switches there for, and'an interrupter in the m'otor circuit tending toopen whenclo's'fed, and-means for holding the nterrupterclbsed, oi electrically 60' controlled meansfor preventing the closure *of theinterrupter. when any portion of t'hestartingl resistance is short-circuit'ed.

- 4 The combination with-an electric supply "circuit, a motonja .startingresistanc'e, and'a65 plurality of short-circuitingswitches [therea ton-Ian automaticinterrupter in the motorcircuit tendingto open when clds'ed, means for 11o1ding the interrupter closed and an 4 ally. controlled mean's' independent of "the 'short cir'cuiting switches for preventing the closure of the interrupter when any p ortion' of'tlie'starting resistance is s'hort-circuite d. U

5 Tlie'combination with an'leotric supply, 7 5 circuit an automatici circuitinterrupter, an electric' motor, a startingresistance therefor" and manually-operated means for gradually short circuiting theiresistarice', of'm'eansoomprising apair-of normally balanced differential 8 0'- rna'g'net coils forpreventing,the'closure of the interrupter when any portion'of the resistance is" shor-t-c'ircuited. v v

6:. 'Th combination with airelectricsupply electric '7 motor, a startingresistance therefor, and manually-operated means for gradually short circu ting the 1-es1stanc'e, of means com risin an eleotro m a neticall controlled p c: e v

net coilsfthere'for for, preventing the closure f of the interrupt'erwhenany portion of the resistance is s hort-cii'cuited I .7'. The combination with 'a supply circuit,

ally-operated control switches; therefor, and

an automatic circuit interrupter, of an elec tro 'magnetica' lly-controlled latch for preventingthe closure of-the circuit interrupter, and differential coils for the'latch which a re, 100 unbalanced when the circuit in er: -1pter is open and, anyone of the control switches'is closed. In testimony whereof, I have hereunto subscribed my name this 28th'day o'fNovem 105 berg-1,9061 v I FLETCHER D'.. HALLOCK.

Witnesses:

DUDLEY A. ,BowERs, 'BIRNEIY Hmns,

overload release magnet thereforot'elect rid- K circuit, ailautomatic circuit interrupter,', an.85

locking device and apair'of 'differential, mag

a motor-starting resistance, a series of ma'nu- 

